Every year, about thirty thousand cases of oral cancer are diagnosed in the United States; for which the basic treatment is surgical excision of hard and soft tissues of the face. Tumor excision may be combined with radiotherapy, which compromises the vascularity of the remaining tissues. Benign tumors of the mandible may also require segmental bone resection due to high incidence of local recurrence after simple curettage or intra-lesion excision. Furthermore, segmental bone loss may result from blast injuries, high impact trauma, or repeated surgical debridement for treatment of chronic osteomyelitis of the mandible. Surgical excision of hard and soft tissues of the head and neck or high impact trauma can lead to major tissue deficits. Reconstruction of the lower jaw typically involves bone, gingiva, and teeth. Current mandibular distraction devices are used in combination with reconstruction plates, but while the reconstruction plates take the contour of the jaw, the distraction devices have a linear vector. The devices also have a limited distraction distance, producing short segments of straight bone and so cannot accommodate large deficits with a single procedure. A robust prototype intra-oral mandibular distraction device (BTRP-01) was built using Phase I STTR funding, and was shown to be mechanically robust, easy to place and use, and able to successfully transport a dentate bone segment across a 2 cm bony gap in a live goat model. The objective of Phase I of this STTR proposal is to create a Finite Element Model (FEM) of human mandibles and of the device, and establish the least robust form of the device to be used in humans that is able to withstand a range of external mechanical forces. We will install and test a Mini Mill Vertical Machining Center for precision manufacturing of the less robust forms of device, and mechanically test these devices to confirm the predictions of the FEM. The purpose of this proposal is to create a less robust form of the device suitable for use in humans in Phase II. Critical features of this proposal are the use of finite element modeling to determine optimal dimensions of the device, and precision manufacturing of smaller, more compact devices for improved treatment and enhanced patient comfort. Every year, about thirty thousand cases of oral cancer are diagnosed in the United States; for which the basic treatment is surgical excision of hard and soft tissues of the face, leading to major tissue deficits. Current mandibular distraction devices are used in combination with reconstruction plates, but while the reconstruction plates take the contour of the jaw, the distraction devices have a linear vector. A robust prototype intra-oral mandibular distraction device was shown to be mechanically robust, easy to place and use, and able to successfully transport a dentate bone segment across a 2 cm bony gap in a live goat model. The objective of Phase I of this STTR proposal is to determine optimal dimensions for precision manufacturing of smaller, more compact devices for improved treatment and enhanced patient comfort. [unreadable] [unreadable] [unreadable]